Generally speaking, ordinary pitch has an amorphous structure. Such pitch is used as a binder in the manufacture of baked carbon bodies such as carbon electrodes. Carbon electrodes are used in the manufacture of steel and in the manufacture of aluminum.
When amorphous pitch is heated to temperatures of at least about 350.degree. C. in an inert gas atmosphere, the molecules of pitch become oriented to give rise to a kind of optically ordered liquid crystal within the pitch. This liquid crystal is called a mesophase. Mesophase pitch is used in the manufacture of high quality carbon fibers. Amorphous pitch is not suitable for use in the carbon fiber process.
A number of different processes have been used for the conversion of various aromatic hydrocarbon feedstocks to mesophase pitch. The process of the invention is an improvement over these prior art processes.